WinTax is a free Canadian payroll tax calculator. WinTax provides users with an easy way to calculate taxes on regular salary, bonus, retroactive pay, and commission. Calculations include CPP, EI, Federal tax, and Provincial tax (including Quebec). WinTax has the following features: save employee information; easy to understand tax calculation reports; Quebec Provincial tax calculation; User definable earnings and deductions. WinTax Calculator can calculate and save payroll tax calculations for one employee for any province.